Method and system for fault tolerance and resilience for virtualized machines in a network

ABSTRACT

Hypervisor functions, which may control operations of one or more virtual machines, may be distributed across a plurality of network devices. State information may be stored for the virtual machines on network devices for fault tolerance and resilience. The virtual machines may retrieve stored state information to recover from a fault. The hypervisor may control the storage of the state information. Resources of the network devices may be allocated for fault tolerance and resilience of the virtual machines based on network device parameters, which may include storage capacity, processor usage, access time, communication bandwidth, and/or latency. The state information may include program content, cache content, memory content, and/or register content information, may be stored on a continuous, periodic, or an aperiodic basis, and may be shared among the network devices to enable the processing of data by the virtual machines when a fault occurs, and may be incrementally updated.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application makes reference to, claims the benefit from, and claims priority to U.S. Provisional Application Ser. No. 61/227,672 filed on Jul. 22, 2009.

This application also makes reference to: U.S. patent application Ser. No. 12/571,296 filed on Sep. 30, 2009.

Each of the above stated applications is hereby incorporated herein by reference in its entirety.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

MICROFICHE/COPYRIGHT REFERENCE

[Not Applicable]

FIELD OF THE INVENTION

Certain embodiments of the invention relate to wired and wireless communication. More specifically, certain embodiments of the invention relate to a method and system for fault tolerance and resilience for virtualized machines in a network.

BACKGROUND OF THE INVENTION

In networking systems, a single machine, for example, a server or a client, may be utilized to concurrently support multiple server operations or services. For example, a single server may be utilized for providing access to business applications while also operating as an email server, a database server, and/or an exchange server. The server may generally support the various server operations by utilizing a single operating system (OS). The server operations, via the single OS, make use of server processing resources such as the central processing unit (CPU), memory, network interface card (NIC), peripheral sound card, and/or graphics card, for example. In many instances, the server resources may not be efficiently utilized because the demand for server operations generally vary based on the type of service provided and/or user needs. Consolidating server services into a single physical machine may result in an improvement in server efficiency. However, consolidation also removes the level of protection that is provided when the operations are maintained separately. For example, when the operations are consolidated, a crash or failure in a database server may also result in the loss of email services, exchange services, and/or application services.

Another approach for improving server efficiency may be to utilize multiple operating systems running concurrently so that each operating system supports a different server operation or application or service, for example. The multiple operating systems may be referred to as guest operating systems (GOSs) or child partitions. This approach maintains the level of protection provided when server operations are not consolidated under a single operating system while also enabling the optimization of the usage of the processing resources available to the server. The use of multiple guest operating systems may be referred to as OS virtualization because each GOS perceives to have full access to the server's hardware resources. In this regard, a GOS is unaware of the presence of any other GOS running on the server. In order to implement OS virtualization, a software layer may be utilized to arbitrate access to the server's hardware resources. This software layer may be referred to as a hypervisor or virtual machine (VM) monitor, for example. The hypervisor may enable the multiple GOSs to access the hardware resources in a time-sharing manner. This software layer may be assisted by a trusted GOS (TGOS), which may also be referred to as a parent partition, or Virtual Machine Kernel (VMK) for instance.

Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.

BRIEF SUMMARY OF THE INVENTION

A system and/or method for fault tolerance and resilience for virtualized machines in a network, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

Various advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram of a single host system virtual machine implementation, which may be utilized in accordance with an embodiment of the invention.

FIG. 2 is a diagram showing exemplary virtual machines with configuration parameters abstracted over a network, in accordance with an embodiment of the invention.

FIG. 3 is a diagram illustrating exemplary threads in abstracted virtual machines, in accordance with an embodiment of the invention.

FIG. 4 is a block diagram illustrating exemplary steps for fault tolerance and resilience for virtualized machines in a network, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain aspects of the invention may be found in a method and system for abstracting virtual machines in a network. In various exemplary aspects of the invention, one or more processors and/or one or more circuits in a plurality of network devices may be operable to distribute hypervisor functions, which may control operations of one or more virtual machines, across a plurality of network devices when processing data by the one or more of the plurality of network devices. Virtual machine process and other state information may be stored for each of the one or more virtual machines on at least one other of the plurality of network devices. The stored state information may be utilized by the one or more virtual machines to provide fault tolerance and resilience when a fault occurs. The one or more virtual machines may retrieve corresponding stored state information when a fault occurs. The one or more virtual machines may recover from the occurrence of a fault utilizing the retrieved corresponding state information when a fault occurs. The hypervisor functions may be operable to control and/or manage the storage of the state information. Resources of the one or more of the plurality of network devices may be allocated for the fault tolerance and resilience of the one or more virtual machines based on network device parameters. In addition, the same mechanism may be used to provide load balancing on networked virtual machines by the state store of a virtual machine on one physical machine and restoring the said virtual machine on another networked physical machine. In an embodiment of the invention, virtual machines may be migrated from one host to another proactively. The network device parameters may comprise storage capacity, processor usage, access time, communication bandwidth, and/or latency parameters. The state information may comprise program content, cache content, memory content, and/or register content information. The state information may be stored on a continuous basis, a periodic basis or an aperiodic basis. The aperiodic basis may include a pre-determined process demarcation point, and may be journaled (incremental state information store). Information may be shared among the plurality of network devices to enable the processing of the data by the one or more virtual machines when the fault occurs. The stored state information for each of the one or more virtual machines may be incrementally updated.

FIG. 1 is a block diagram of a single host system virtual machine implementation, which may be utilized in accordance with an embodiment of the invention. Referring to FIG. 1, there is shown an exemplary network interface card (NIC) 110 that supports level 2 (L2) switching and/or higher layer of switching for communication between virtual machines (VMs) in a host system. The switching supported by the NIC 110 need not be limited to L2 only, and may be any combination of L2, VLAN, L3, L4, higher protocol layer and/or additional information including from the administrator as to how to perform the switching. There is also shown virtual machines (VMs) 102 a, 102 b, and 102 c, a transfer virtual machine (TVM) 102 d, a hypervisor 104, a host system 106, and a NIC 110. The TVM 102 d may comprise a main driver 124. The host system 106 may comprise a host processor 122 and a host memory 120. The NIC 110 may comprise a NIC processor 118, a NIC memory 116, a L2 switch 130, and a physical address validator 132.

The host system 106 may comprise suitable logic, circuitry, interfaces, and/or code that may enable data processing and/or networking operations, for example. In some instances, the host system 106 may also comprise other hardware resources such as a graphics card and/or a peripheral sound card, for example. The host system 106 may support the operation of the VMs 102 a, 102 b, and 102 c via the hypervisor 104. The VMs 102 a, 102 b, and 102 c may each correspond to an operating system, for example, that may enable the running or execution of operations or services such as applications, email server operations, database server operations, and/or exchange server operations, for example. The number of VMs that may be supported by the host system 106 by utilizing the hypervisor 104 need not be limited to any specific number. For example, one or more VMs may be supported by the host system 106. Internal switching may occur between VMs or between a VM and the TVM 102 d.

The hypervisor 104 and/or the TVM 102 d may operate as a software layer that may enable virtualization of hardware resources in the host system 106 and/or virtualization of hardware resources communicatively connected to the host system 106, such as the NIC 110, for example. The hypervisor 104 and/or the TVM 102 d may allocate hardware resources and also may enable data communication between the VMs and hardware resources in the host system 106 and/or hardware resources communicatively connected to the host system 106. For example, the hypervisor 104 may enable communication between the VMs supported by the host system 106 and the NIC 110. In instances where a relevant VM is engaged in network transmission or reception, data may travel directly to/from the NIC after the TVM 102 d has allocated queues, internal resources required on the NIC, consulted with the configuration and administrative information. The hypervisor 104 may comprise a sub-hypervisor 108 that may facilitate the mapping of local VM resources and remote VM resources over the network. The sub-hypervisor 108 may further facilitate local VMs' state storage on a network resources. The sub-hypervisor 108 may communicate with the hypervisor 104 that may reside in the network to provide locally available virtual machine resources in the host system 106.

The TVM 102 d may comprise a main driver 124 that may coordinate the transfer of data between the VMs. The main driver 124 may communicate with the virtual NIC driver 126 a in the VM 102 a, the virtual NIC driver 126 b in the VM 102 b, and/or the virtual NIC driver 126 c in the VM 102 c. Each virtual NIC driver may correspond to a portion of a VM that may enable transfer of data between the operations or services performed by the VMs and the appropriate queues via the main driver 124.

The host processor 122 may comprise suitable logic, circuitry, interfaces, and/or code that may be operable to control and/or management of the data processing and/or networking operations associated with the host system 106. The host memory 120 may comprise suitable logic, circuitry, and/or code that may enable storage of data utilized by the host system 106. The host memory 120 may be partitioned into a plurality of memory portions. For example, each VM supported by the host system 106 may have a corresponding memory portion in the host memory 120. Moreover, the hypervisor 104 may have a corresponding memory portion in the host memory 120. In this regard, the hypervisor 104 and/or the TVM 102 d may enable data communication between VMs by controlling the transfer of data from a portion of the memory 120 that corresponds to one VM to another portion of the memory 120 that corresponds to another VM.

The NIC 110 may comprise suitable logic, circuitry, interfaces, and/or code that may enable communication of data with a network. The NIC 110 may enable basic L2 switching, VLAN based switching, TCP offload, iSCSI, and/or RDMA operations, for example. The NIC 110 may be referred to a virtualization-aware NIC because communication with each VM may occur by an independent set of queues. The NIC 110 may determine the right address or combination of address information, such as, for example, VLAN address, L2 MAC address, L3 IP address, L4 port, among others, to be used in order to select the right target VM. For instance, the NIC 110 may determine the MAC address of received packets and may transfer the received packets to an RX queue that corresponds to the VM with the appropriate MAC address. Similarly, the NIC 110 may enable transfer of packets from the VMs to the network by coordinating and/or arbitrating the order in which packets posted for transmission in TX queues may be transmitted. In this regard, the NIC 110 is said to enable direct input/output (I/O) or hypervisor bypass operations.

Some embodiments of the invention may comprise the NIC 110 that may allow validation, correction, and/or generation of, for example, MAC addresses or VLAN tags or IP addresses or attributes like TOS bits in IP headers. For example, the NIC 110 may detect that a VM may request a packet to be sent with a wrong source MAC address. The NIC 110 may validate a source MAC address by, for example, comparing the source MAC address for a packet with MAC addresses that may be associated with specific VM or buffers, and/or packet types.

The NIC 110 may flag the wrong source MAC address as an error to the TVM and/or to the VM, and may discard the packet. Another embodiment of the invention may enable the NIC 110 to overwrite the incorrect parameter or attribute, for example, the source MAC address for the packet from a VM with a correct source MAC address, and proceed with transmitting the packet. Similarly, another embodiment of the invention may generate an appropriate source MAC address for each packet from the VMs without validating the source MAC address. Accordingly, an application program running on a VM may not need to generate a source MAC address as the NIC 110 may write the source MAC address. The NIC 110 may also monitor use of bandwidth and/or priority per VM. The NIC 110 may, for example, allocate bandwidth limits or frames per VM, and/or ensure that VM or applications or flows associated with a VM do not claim priority different than that assigned by the administrator and/or TVM.

The NIC processor 118 may comprise suitable logic, circuitry, interfaces, and/or code that may enable control and/or management of the data processing and/or networking operations in the NIC 110. The NIC memory 116 may comprise suitable logic, circuitry, and/or code that may enable storage of data utilized by the NIC 110. The NIC 110 may be shared by a plurality of VMs 102 a, 102 b, and 102 c. In some embodiments of the invention, network protocol operations may be offloaded to the NIC 110 and handled by the NIC 110. The offloaded network protocol operations may comprise OSI layer 3, 4, and/or 5 protocol operations, such as, for example, TCP and/or IP operations. The NIC may also execute link layer network protocol operations, which may be, for example, OSI layer 2 protocol operations, for example, a VLAN.

Accordingly, the NIC 110 may be a shared resource for the plurality of VMs. The operations of the VMs and the NIC may be coordinated by the TVM 102 d and the hypervisor 104. Operation of a VM and a NIC may comprise copying data between a VM and the NIC. This may be accomplished by the NIC when the VM communicates to the NIC an address of a buffer or a reference to an address of a buffer to be accessed in that VM. The address may be a physical address or a virtual address. A virtual address may be translated to a physical address via, for example, an address translation table or a memory management unit. The means of address translation may be design and/or implementation dependent.

The L2 switch 130 may comprise suitable logic, circuitry, and/or code that may enable the NIC 110 to support packet communication between a VM and the network and/or between VMs, for example. Placing switching functionality in the NIC 110 may, for example, reduce end-to-end latency when transmitting or receiving packets. The L2 switch 130 may support unicast, broadcast, and/or multicast operations. Unicast operations may refer to packet transmissions to a single MAC address. Broadcast operations may refer to packet transmissions to all MAC addresses. Multicast operations may refer to packet transmission to a particular group of MAC addresses.

For example, the VM 102 a may send a packet to at least one device communicatively coupled to the network. In this instance, the virtual NIC driver 126 a may transfer the packet to a TX queue corresponding to the VM 102 a. The L2 switch 130 may receive the packet from the appropriate TX queue and may determine that the destination MAC address or addresses correspond to a device or devices on the network. The NIC 110 may then communicate the packet to the network.

In another example, the VM 102 a may have a data packet to transmit to the VM 102 b and/or the VM 102 c. In this instance, the virtual NIC driver 126 a may place the data packet on a TX queue corresponding to the VM 102 a. The L2 switch 130 may receive the data packet from the TX queue and may determine that the destination MAC address may correspond to the VM 102 b. The NIC 110 may place, for example, the data packet in to an RX queue corresponding to the VM 102 b. The virtual NIC driver 126 b may be notified of the data packet in the RX queue via the event queue 112 a, and the virtual NIC driver 126 b may copy the data packet for use by an application program on the VM 102 b.

The NIC 110 may also comprise the physical address validator 132. The physical address validator 132 may comprise suitable logic, circuitry, and/or code that may enable the validation of the address of a buffer posted by a virtual NIC driver to store a received packet. For example, before a packet in an RX queue is transferred to a posted buffer, the physical address validator 132 may validate that the posted buffer is in an address or memory location that corresponds to the VM associated with the received packet. When the address is validated, the received packet may be transferred from the RX queue to the posted buffer. If the physical address cannot be validated, the NIC 110 may notify, for example, the TVM and/or the hypervisor and/or the main driver 124 and/or virtual NIC driver 126 a. Accordingly, the virtual NIC driver 126 a may post a new buffer to receive the packet from the RX queue or another action such as bringing down the virtual drive may be taken by the TVM and/or hypervisor. Similar validation for transmit buffer addresses can be performed by the NIC.

FIG. 2 is a diagram showing exemplary virtual machines with configuration parameters abstracted over a network, in accordance with an embodiment of the invention. Referring to FIG. 2, there is shown devices 201A-201F, virtual machines (VMs) 203A and 203B, a network 205, a hypervisor 207, and sub-hypervisors 209A and 209B.

The devices 201A-201F may comprise suitable circuitry, logic, interfaces, and/or code that may be operable to support the implementation of multiple virtual machines, such as the VMs 203A and 203B, and may comprise desktop computers, servers, switches, personal data assistants, smart phones, routers, racks, blades, mainframes, laptop devices and/or or any hardware that may support VM functionality. Various portions of the hardware requirements of the VMs 203A and 203B may be supported on a particular device based on the suitability of the device for that purpose, including metrics such as processor speed, storage space, current usage, network media connectivity, network bandwidth, and load balancing, for example.

The VMs 203A and 203B may comprise suitable circuitry, logic, interfaces, and/or code that may be operable to perform functions of a machine utilizing software. For example, a VM may comprise an operating system (OS), such as Windows XP, Linux, or the Mac OS, distributed across the network 205. The VMs 203A and 203B may be distributed over a plurality of devices in the network 205 and may be configured for optimum performance utilizing information regarding capabilities of the various devices used to support a particular VM. For example, a VM that may be utilized to perform intensive calculations may be partially supported by a device with high floating-point operations per second (FLOPs) processor capability.

The network 205 may comprise a local area network (LAN), a personal area network (PAN, an enterprise network, or any collection of devices in communication with each other and with the ability to be controlled by a single entity, for example.

The hypervisor 207 may comprise functionality similar to the hypervisor 104 described with respect to FIG. 1, but abstracted, or distributed, over the network 205. In this manner, various functionalities of the VMs 203A and 203B may be controlled while distributed over a plurality of devices, such as the devices 201A-201F. The hypervisor 207 may allocate hardware and software resources and also may enable data communication between the VMs and hardware resources in the devices 201A-201F. For example, the hypervisor 207 may enable communication between the VMs supported devices 201A-201F. In another embodiment of the invention, the hypervisor 207 may control the overall operation of the VMs 203A and 203B, controlling the flow of information between the various devices supporting the VM, and may control the sub-hypervisors 209A and 209B in the VMs 203A and 203B, respectively, essentially comprising a networked hypervisor not tied to any one device. The networked sub-hypervisors may reside in each local hypervisor of devices 201A-201F.

For the hypervisor 207 to be abstracted in the network 205, the devices 205A-205F may be aware of communication of information to and from processors in the devices 205A-205F as well as configurations of the various devices 205A-205F controlled by the hypervisor 207. Communicated information may comprise the state of a VM and network 205 and device 205A-205F resources used by the VMs. In this manner, load balancing may be configured, optimizing the performance of the VMs 203A and 203B. For example, since the hypervisor 207 and the sub-hypervisors 209A and 209B may be distributed over the network 205, they may be network-aware as opposed to just aware of resources in a single device. Thus, the VM parameters may be shared among the devices 201A-201F, enabling the dynamic prioritization and resource allocation of the networked devices.

The sub-hypervisors 209A and 209B may comprise suitable circuitry, logic, interfaces, and/or code that may be operable to control operations within a particular VM, while under the control of the hypervisor 207. The sub-hypervisors 209A and 209B may control sub-operations in the VMs 203A and 203B respectively. The sub-hypervisors 209A and 209B may communicate load information of network devices, in which a particular VM may be located, back to the hypervisor 207. The sub-hypervisors 209A and 209B may comprise an of sub-set of hypervisor functions per individual networked VM, such that each VM management and embodiment could be optimized for performance and reliability. The sub-hypervisor 209A and 209B functionality may comprise control and management of memory, I/O coherence, buffers, cache, VM process state save, network interface of VM, while the hypervisor 207 functionality may comprise control and management of device resources, and actions such as VM creation, VM state save, VM state restoration, and VM deletion. The sub-hypervisors 209A and 209B may reside in the network or in devices 201A-201F.

The virtual machine state information (VMSI) 211A and 211B may comprise parameters that define the state of the VMs 203A and 203B. This may comprise locations and status of components of the devices 201A-201F that support a particular function, thread, or component of the VM 203A or 203B. The VMSI 211A and 211B may comprise parameters such as program content, instruction and data cache content, memory content, and/or register content, for example. The VMSI 211A and 211B may be stored on one or more of the devices 201A-201F that may be utilized to support a particular VM thereby enabling redundancy in the resilience and fault tolerance in the case of a failure or fault.

In operation, the VMs 203A and 203B may be enabled to operate utilizing a plurality of the devices 201A-201F. For example, the virtual machine 203A may be distributed over the devices 201A-201D, and the VM 203B may be distribute over the devices 201C-201F. The devices 201A-201F may be within the network 205, and may share VM parameters so that specified functions within the VMs may be executed within a device with preferred performance with respect to that function. For example, a device with high processor speed may be utilized for processor-intensive functions of the VM, and storage-intensive operations may be executed on devices local to the required storage capacity to utilize a higher bandwidth connection to the storage capacity.

The hypervisor 206 may control the overall distribution and/or configuration of the functionality of the VMs, and may perform load balancing, managing resources in devices across the network 205, thereby enabling scaling and optimization of performance dependent on available network resources, for example. The hypervisor 207 may enable configuration of multiple VMs across the network 205, which would not enabled with a non-abstracted hypervisor. The hypervisor 207 may control the VMs 203A and 203B via the sub-hypervisors 209A and 209B within the VMs. The communication and available resource parameters may be communicated to the VMs 203A and 203B via the hypervisor 207. The sub-hypervisors 209A and 209B may communicate the compute load of a particular VM to the hypervisor 207 so that it may configure resources to individual VMs based on the hypervisor 207 traffic awareness. The sub-hypervisor 209A may communicate greater computing needs of the VM 203A and the hypervisor 207 may assign more compute resources to VM 203A, for example. Accordingly, because the VMs are distributed over networked resources, the VMs are scalable limited only by the resources available in the networked resources.

The VMSI 211A and 211B may be stored on a continuous (journaled, for example), periodic and/or aperiodic basis, such that in instances when one or more of the devices 201A-201F or resources in the devices that may be supporting a particular VM fails, the last stored state in the VMSI 211A or 211B may be utilized by the hypervisor 207 to re-establish the affected VM. The hypervisor 207 may configure the VMs 203A and 203B based on parameters of the network devices 201A-201F where the parameters may comprise storage capacity, processor usage, access time, communication bandwidth, availability, local fault tolerance and redundancy, and/or latency, for example. The hypervisor 207 may communicate parameters to the network devices 201A-201F using protocols such as energy efficient Ethernet (EEE) or simple network management protocol (SMNP), for example.

FIG. 3 is a diagram illustrating exemplary threads in abstracted virtual machines, in accordance with an embodiment of the invention. Referring to FIG. 3, there is shown the network 205, the devices 201A-201F, and the hypervisor 207, which may be as described with respect to FIG. 2. There is also shown virtual machines 303A and 303B, which comprise threads 301A-301D and the VMSIs 305A and 305B. The VMSIs 305A and 305B may be substantially similar to the VMSIs 211A and 211B described with respect to FIG. 2. The threads 301A-301D may comprise the suitable circuitry, logic, and or code that may be operable to perform specific functions within the VMs. A VM may comprise a plurality of threads, such as the threads 301A and 301 b in the VM 303A and the threads 301C and 301D in the VM 303B, for example.

In operation, the threads 301A-301D may be enabled to execute various functions in the VMs 303A and 303B, and may be controlled by the hypervisor 207, which may be abstracted over the devices 201A-201F, for example. The threads may also be distributed over a plurality of devices. For example, the thread 301D may be distributed over the devices 201A-201E, and the thread 301A may be distributed over the devices 201A-201C. In this manner, resources from different devices may be utilized in a thread in a VM to optimize performance and to load balance. For example, if a function in a VM requires significant processing capability, a thread may be configured to reside partially on a device comprising suitable processor power. The configuration of the threads 301A-301D may be dynamically controlled by the hypervisor 207, and may be adjusted based on changing network or resource utilization conditions, for example. In addition, a “green” aspect may be enabled by the hypervisor 207 or the sub-hypervisors 209A and 209B. For example, devices may be turned on or off to use more/less power based on VM computing demands from the networked hypervisor 207.

The VMSIs 305A and 305B may be stored on devices utilized to support a particular VM. Accordingly, the VMSI 305A may be stored on any or all of the devices 201A-201C that may support the VM 303A, and the VMSI 305B may be stored on any or all of the devices 201A-201F that may support the VM 303B. In instances where a device 201A-201F fails or a resource within a device fails, the hypervisor 207 may recall the last VMSI 303A and/or 303B that was stored on one or more of the devices 201A-201F before the failure, and reestablish the VM 303A and/or 303B using the recalled VM state parameters.

In instances where the device 201F may be under-utilized, such as when comprising the VM 303B only, the same VMSI state parameters may be used to move (state store, halt, and restore, for example) the thread 301C from VM 303B in device 201F onto the device 201A, thereby freeing up the device 201F and allowing it to go to a lower-power standby mode. In instances where the thread 301D may require more compute resources, the same VMSI state parameters may be used to move the thread 301D from the device 201A (which supports many threads in this example) onto the device 201F that is either lightly loaded or may be a higher performance compute server.

FIG. 4 is a block diagram illustrating exemplary steps for fault tolerance and resilience for virtualized machines in a network, in accordance with an embodiment of the invention. Referring to FIG. 4, in step 403 after start step 401, the hypervisor 207 may configure VMs over the available networked devices. In step 405, the parameters established for the VMs may be stored amongst the networked devices, followed by step 407, where the VMs may execute their desired functions. If, in step 409, there is a failure of a network device or a resource in the network device, the exemplary steps may proceed to step 411 where the last stored state information before the network device or resource failure is recalled or retrieved before proceeding to step 403. If, in step 409, there is no network device or resource failure, the exemplary steps may proceed to step 410. Steps 410, 415, and 417, illustrates exemplary steps for load balancing of virtualized machines in a network where a lightly loaded physical device may transfer its VM process to others, or a VM process that demands more resources may migrate to a lightly loaded physical device. In step 410, if a hypervisor is instructed to load-balance, it may the exemplary steps may proceed to step 415 where the hypervisor may halts the VM. In step 417, the hypervisor may create a VM in a target host before proceeding to step 411, where the VM process may be restored. If in step 410 the hypervisor is not instructed to load-balance, the exemplary steps may proceed to end step 413.

In an embodiment of the invention, a method and system are disclosed for fault tolerance and resilience for virtualized machines in a network. In this regard, one or more processors and/or one or more circuits in a plurality of network devices 201A-201F may be operable to distribute hypervisor functions, which may control operations of one or more virtual machines 203A, 203B, 303A, and 303B, across a plurality of network devices 201A-201F when processing data by the one or more of the plurality of network devices 201A-201F. State information 211A and 211B may be stored for each of the one or more virtual machines 203A, 203B, 303A, and 303B on at least one other of the plurality of network devices 201A-201F, wherein the stored state information 211A and 211B may be utilized by the one or more virtual machines 203A, 203B, 303A, and 303B for fault tolerance and resilience. The one or more virtual machines 203A, 203B, 303A, and 303B may retrieve corresponding stored state information when a fault occurs.

The one or more virtual machines 203A, 203B, 303A, and 303B may be operable to recover from the occurrence of a fault utilizing the retrieved corresponding state information when a fault occurs. The hypervisor 207 functions may be operable to control and/or manage the storage of the state information 211A and 211B. Resources of the one or more of the plurality of network devices 201A-201F may be allocated for the fault tolerance and resilience of the one or more virtual machines 203A, 203B, 303A, and 303B based on network device parameters. The network device parameters may comprise storage capacity, processor usage, access time, communication bandwidth, and/or latency parameters. The state information 211A and 211B may comprise program content, cache content, memory content, and/or register content information. The state information 211A and 211B may be stored on a continuous basis, a periodic basis or an aperiodic basis. Information may be shared among the plurality of network devices 201A-201F to enable the processing of the data by the one or more virtual machines 203A, 203B, 303A, and 303B when the fault occurs. The stored state information 211A and 211B for each of the one or more virtual machines 203A, 203B, 303A, and 303B may be incrementally updated.

Another embodiment of the invention may provide a machine and/or computer readable storage and/or medium, having stored thereon, a machine code and/or a computer program having at least one code section executable by a machine and/or a computer, thereby causing the machine and/or computer to perform the steps as described herein for fault tolerance and resilience for virtualized machines in a network.

Accordingly, aspects of the invention may be realized in hardware, software, firmware or a combination thereof. The invention may be realized in a centralized fashion in at least one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware, software and firmware may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.

One embodiment of the present invention may be implemented as a board level product, as a single chip, application specific integrated circuit (ASIC), or with varying levels integrated on a single chip with other portions of the system as separate components. The degree of integration of the system will primarily be determined by speed and cost considerations. Because of the sophisticated nature of modern processors, it is possible to utilize a commercially available processor, which may be implemented external to an ASIC implementation of the present system. Alternatively, if the processor is available as an ASIC core or logic block, then the commercially available processor may be implemented as part of an ASIC device with various functions implemented as firmware.

The present invention may also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context may mean, for example, any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form. However, other meanings of computer program within the understanding of those skilled in the art are also contemplated by the present invention.

While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiments disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims. 

What is claimed is:
 1. A method for communication, the method comprising: performing by one or more processors or circuits in one or more of a plurality of network devices: distributing hypervisor functions, which control flow of information among one or more virtual machines, across a plurality of network devices, including distributing first hypervisor functions for processing the first hypervisor functions on a first network device, and distributing second hypervisor functions for processing the second hypervisor functions on a second network device; simultaneously processing data by said plurality of network devices, including processing respective portions of operations of a first virtual machine on a first plurality of network devices of the plurality of network devices; simultaneously processing respective portions of operations of a second virtual machine on a second plurality of network devices of the plurality of network devices; processing the first hypervisor functions on the first network device, and simultaneously processing the second hypervisor functions on the second network device; storing state information for each of said one or more virtual machines on at least one other of said plurality of network devices; detecting failure of a network device of the first network device and the second network device; retrieving the last stored state information for each of said one or more virtual machines from the at least one other of said plurality of network devices; reconfiguring the one or more virtual machines on remaining network devices of the plurality of network devices using the retrieved last stored state information.
 2. The method according to claim 1, wherein said hypervisor functions are operable to control or manage said storage of said state information.
 3. The method according to claim 2, comprising allocating resources of said one or more of said plurality of network devices for said fault tolerance and resilience of said one or more virtual machines based on network device parameters.
 4. The method according to claim 1, comprising allocating resources of said one or more of said plurality of network devices for load-balancing of said one or more virtual machines based on network device parameters.
 5. The method according to claim 4, wherein said network device parameters comprise storage capacity, processor usage, access time, communication bandwidth, or latency parameters.
 6. The method according to claim 1, wherein said state information comprises program content, cache content, memory content, or register content information.
 7. The method according to claim 1, comprising storing said state information on a continuous basis, a periodic basis or an aperiodic basis.
 8. The method according to claim 1, comprising sharing information among said plurality of network devices to enable said processing of said data by said one or more virtual machines when said fault occurs.
 9. The method according to claim 1, comprising incrementally updating said stored state information for each of said one or more virtual machines.
 10. A system for enabling data processing, the system comprising: one or more processors or circuits in a plurality of networked devices, said one or more processors or circuits are operable to: distribute hypervisor functions, which control operations of one or more virtual machines, across a plurality of network devices when processing data by said one or more of said plurality of network devices, including distributing first hypervisor functions for processing on a first network device and distributing second hypervisor functions for processing on a second network device; simultaneously process respective portions of data by respective network devices of said plurality of network devices, including processing the first hypervisor functions on the first network device during a particular time interval and processing the second hypervisor functions during the particular time interval on the second network device; and store state information for each of said one or more virtual machines on at least one other of said plurality of network devices; detect occurrence of a fault by a network device of said plurality of network devices; recall said stored state information by said distributed hypervisor functions; reconfigure remaining network devices of the plurality of network devices using the recalled stored state information to reestablish said one or more virtual machines.
 11. The system according to claim 10, wherein said one or more virtual machines recovers from said occurrence of said fault utilizing said retrieved corresponding state information when a fault occurs.
 12. The system according to claim 10, wherein said hypervisor functions are operable to control or manage said storage of said state information.
 13. The system according to claim 12, wherein said one or more processors or circuits are operable to allocate resources of said one or more of said plurality of network devices for said fault tolerance and resilience of said one or more virtual machines based on network device parameters.
 14. The system according to claim 10, wherein said one or more processors or circuits are operable to allocate resources of said one or more of said plurality of network devices for load-balancing of said one or more virtual machines based on network device parameters.
 15. The system according to claim 14, wherein said network device parameters comprise storage capacity, processor usage, access time, communication bandwidth, or latency parameters.
 16. The system according to claim 10, wherein said state information comprise program content, cache content, memory content, and/or register content information.
 17. The system according to claim 10, wherein said one or more processors and/or circuits are operable to store said state information on a continuous basis, a periodic basis or an aperiodic basis.
 18. The system according to claim 10, wherein said one or more processors and/or circuits are operable to share information among said plurality of network devices to enable said processing of said data by said one or more virtual machines when said fault occurs.
 19. The system according to claim 10, wherein said one or more processors and/or circuits are operable to incrementally update said stored state information for each of said one or more virtual machines.
 20. A method comprising: distributing hypervisor functions of a hypervisor across respective network computers of a plurality of network computers; by the respective network computers implementing the hypervisor, configuring a plurality of virtual machines over the plurality of network computers so that respective portions of each virtual machine are performed on respective network computers of the plurality of network computers; by the respective network computers implementing the hypervisor, controlling communication among the plurality of virtual machines and the plurality of network computers; storing state information for each of the plurality of virtual machines on at least one other of said plurality of network computers; by the respective network computers implementing the hypervisor, detecting a condition requiring reconfiguration of the plurality of virtual machines among the network computers; and in response to the condition requiring reconfiguration of the plurality of virtual machines, retrieving the last stored state information for each of said plurality of virtual machines from the at least one other of the plurality of network computers; and reconfiguring the one or more virtual machines on the plurality of network computers using the retrieved last stored state information.
 21. The method of claim 20 wherein detecting a condition requiring reconfiguration of the plurality of virtual machines among the network computers comprises detecting failure of a network computer of the plurality of network computers, and wherein reconfiguring the one or more virtual machines comprises reconfiguring the one or more virtual machines on remaining network computers of the plurality of network computers using the retrieved last stored state information.
 22. The method of claim 20 wherein configuring a plurality of virtual machines over the plurality of network computers comprises matching a function of a respective portion of a virtual machine with a respective network computer best suited for performing the function of the respective portion of the virtual machine. 